Isotria medeoloides

Herbs, singly or rarely in small clumps, short-rhizomatous, 4–25 cm. Stems pale grayish green, glaucous; scales 2–4, near soil line, white to light green. Leaves pale grayish green; blade elliptic-obovate, 17–85 × 8–40 mm, apex acuminate, glaucous when young. Flowers subsessile, without nectar and fragrance; sepals arching, green to light green, linear-oblanceolate, 12–25 × 2–3 mm; petals light green, oblanceolate, 12–18 × 2–4 mm; lip light yellowish green to pale greenish white, streaked with green, obovate, 11–16 × 4–5 mm, lateral lobes narrowly triangular, margins involute, middle lobe rounded, margins slightly revolute, undulate; callus yellowish green, longitudinal, becoming elongate, with fleshy, wartlike papillae toward apex; column 8–10 mm; ovary 10–15 mm; rostellar flap reduced. Capsules 12–28 × 2–10 mm; pedicel of mature capsule elongating to 5–17(–20, rarely) mm. 2n = 18.

Phenology: Flowering May–Jun; capsules mature fall.
Habitat: Acidic soils, in dry to mesic 2d-growth, deciduous or deciduous-coniferous forests, typically light to moderate leaf litter, open herb layer (occasionally in dense ferns), moderate to light shrub layer, relatively open canopy, frequently on flats or slope bases near canopy breaks
Elevation: 30–1000 m

Distribution

• Generated Map
• Legacy Map

Ont., Conn., Del., Ga., Ill., Maine, Md., Mass., Mich., Mo., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., S.C., Tenn., Vt., Va.

Discussion

Isotria medeoloides should be sought in Alabama, Arkansas, Indiana, Kentucky, and West Virginia.

Isotria medeoloides is self-pollinating (L. A. Mehrhoff 1983). Nonflowering plants commonly have a white, arrested floral bud (1–2 mm).

of conservation concern

Selected References

Brumback, W. E. and C. W. Fyler. 1988. Monitoring of Isotria medeoloides in New Hampshire. Wild Fl. Notes 3: 32–40.

Dyer, R. W. 1986. Small whorled pogonia. Audubon Wildlife Rep. 1986: 780–789.

Mehrhoff, L. A. 1989. Reproductive vigor and environmental factors in populations of an endangered North American orchid, Isotria medeoloides (Pursh) Rafinesque. Biol. Conservation 47: 281–296.

Mehrhoff, L. A. 1989b. The dynamics of declining populations of an endangered orchid, Isotria medeoloides. Ecology 70: 783–786.

Oettingen, S. L. 1992. Small Whorled Pogonia (Isotria medeoloides) Recovery Plan: First Revision. Washington.

Paulos, P. G. 1985. Small Whorled Pogonia Recovery Plan. [Newton Corner, Mass.]

Lower Taxa

None.